In commercial vehicles, for example trucks, the transmissions used are most often manually shifted transmissions or automated manually shifted transmissions. Manually shifted and automated manually shifted transmissions are noted for high efficiency along with low purchase costs. In such manually shifted and automated manually shifted transmissions, shifting operations take place with traction force interruption.
In passenger cars the transmissions used are more and more often dual clutch transmissions. In dual clutch transmissions shifts can be carried out without traction force interruption. However, dual clutch transmissions are characterized by larger dimensions, higher weight and higher purchase costs. Furthermore, for use in commercial vehicles, in which the dual clutch transmission should then be designed as a so-termed group transmission, dual clutch transmissions are not always suitable. One of the reasons for this is that with a dual clutch transmission geometrical gear steps, particularly in the lower gears, lead to gear intervals that are too small so that a large number of shifts have to be carried out. By virtue of the system, skipping individual gears is not possible in a dual clutch transmission.
From DE 10 2011 087 947 A1 a motor vehicle transmission designed as a group transmission with a main transmission and a downstream group connected downstream from the main transmission is known, wherein planetary gearsets or planetary gear stages are used in both the main transmission and the downstream group of the group transmission.
From DE 10 2005 002 337 A1 a further motor vehicle transmission is known, which uses a plurality of planetary gearsets or planetary gear stages.